As a photoelectric conversion device to be used for solar photovoltaic power generation, a device provided with a plurality of photoelectric conversion cells on a substrate is exemplified as disclosed in Japanese Unexamined Patent Application Publication No. 2000-299486.
Such a photoelectric conversion device is formed by two-dimensionally arranging a plurality of photoelectric conversion cells in which a lower electrode layer such as a metal electrode, a light-absorbing layer, a buffer layer, and a transparent conductive film are stacked in this order on a substrate such as glass. The plurality of photoelectric conversion cells are electrically connected in series by connecting the transparent conductive film of one of the adjacent photoelectric conversion cells and the lower electrode layer of the other of the adjacent photoelectric conversion cells through a connection conductor.
Improvement of photoelectric conversion efficiency is constantly demanded for the photoelectric conversion device. In the photoelectric conversion device, a method of increasing the size of crystal grains of a semiconductor layer serving as a light-absorbing layer may be considered as a method for improving the photoelectric conversion efficiency. However, when the size of the crystal grains of the semiconductor layer is increased, cracks easily appear on the semiconductor layer due to thermal stress or the like and it is difficult to sufficiently improve the photoelectric conversion efficiency.